Mounting adaptor assemblies heretofore have been used to mount grinding wheels or the like to the tapered ends of rotatably driven shafts. Typically, the grinding wheel is concentrically mounted on an adaptor which has a tapered axial center bore for mounting on the correspondingly tapered end of the rotatably driven shaft. The shaft has been provided with a threaded cylindrical end portion onto which an adaptor lock nut is threaded to hold the adaptor in tight frictional engagement with the taper of the shaft. The angle of the taper is selected to ensure positive gripping of the adaptor on the shaft for common rotation. Pulleys to drive to be driven by a belt have been similarly mounted to a shaft.
Because of the snug fit of the adaptor or pulley on the tapered end of the shaft, demounting of the adaptor or pulley has been difficult. A common practice has been to pry or hammer the adaptor or pulley to effect its release from the shaft, but this may result in damage to it or the shaft and also to other components of the apparatus in which the shaft is mounted. Another practice has been to use a gear puller or similar tool to release the adaptor or pulley, but this was a relatively time consuming task and there was still the possibility of damaging the adaptor or pulley.